Many different disease-causing microbes, or pathogens, can contaminate foods, so there are many different foodborne infections. Harmful toxins or chemicals can also contaminate food, for example, poisonous mushrooms. The microbes or toxins enter the body through the gastrointestinal tract, and often cause the first symptoms. Nausea, vomiting, abdominal cramps and diarrhea are common symptoms in many foodborne diseases. Many microbes can spread in more than one way, so we cannot always know that a disease is foodborne. The distinction matters, because public health authorities need to know how a particular disease is spreading to take the appropriate steps to stop it. For example, Escherichia coli O157:H7 infections can spread through contaminated food, contaminated drinking water, contaminated swimming water, and from toddler to toddler at a day care center. Depending on which means of spread caused a case, the measures to stop other cases from occurring could range from removing contaminated food from stores, chlorinating a swimming pool, or closing a child day care center. The long-term goal of this project is to develop a simple-to-use and inexpensive lateral flow strip test with high sensitivity and selectivity for the multiplexed detection of bacterial toxins that cause foodborne illnesses. Selectivity and sensitivity will be achieved using antibodies that specifically bind to the target toxins. The antibodies will be bound to dye-doped silica nanoparticles, which will provide visual indication of bacterial toxin contamination. Positive identification of toxins in a test sample is based on the engineering and design of the test strip - each type of toxin will produce a unique color change at a specific location on the strip. The test strips can be used by a multitude of different companies and agencies within the public, private, and government sectors for monitoring food and beverage quality with extended future applications for diagnostics in the healthcare industry. The specific aims for the Phase I project are: Aim 1 Synthesize dye-doped silica nanoparticles and modify with toxin-specific antibodies, Aim 2 Identify materials and additives that will provide optimal test strip performance and assemble test strips, Aim 3 Evaluate the response of the test strips to target three different toxins in inoculated buffer samples and to food/beverage simulants, and Aim 4 Integrate Phase I findings to design the multi-analyte test strip to be developed in Phase II.